Extracting metals from sulfid ores.



PATENTBD JAN. 8, 1907.

R. L. PACKARD. EXTRAQIING METALS FROM SULFID 0am.

APPLICATION FILED JAN. 11

* UNITE sTA r js PATENT OFFICE.

ROBERT" La -PACKARD, onwasiaiuerou. msrriuerosco UMBIa.

' GXTRAQTI NGiME-TAL ,Fnom SULFID onEs.

Specification of Letters Patent. Application filed January ii,19oe. Serial No. 296,661.

Patented Jan. 8, 1907.

To all whom it may concern:

l Be itk'nown that I, ROBERT L. PAoxAaD,

.. a citizen of the United States, residing at ,Washington, District of Columbia, have invented certain new and useful Improvements in Extracting Metals from Sulnd Ores, of which the following is a specification;

' This invention relates to the'treatment of I sulfid ores, particularly sulfids of copper and zinc, in the wet way, whereby the said sulfids are converted into sulfates and the metals of such sulfates as are soluble are .brought I into solution and'are subsequently recovered.

Copper and zinc are usually obtained from their sulfid ores by some smelting process,

which is sometimes preceded by roasting, andsometimes the ores are roasted to a certain point and then treated in the wet Way.

The roasting of sulfid ores is essentiallyan oxidizing process and may be carried so far as to eliminate all or nearly all the sulfur and leave the metals as oxids,,or it may be so conducted as to convert them into sulfates. either case expensive furnaces, costly fuel,

and skilled labor are necessary to carry out the process, and only ores ofsufficiently high value toyield a profit over and above the expense of the metallurgical operations, plus I the cost eftransportiomcan-be smelte'd. By

my invention furnaces and their attendant expenses are dispensed with, so that ores of copper of too low grade to bear the cost of "transportation and smelting can be pro'fit tact with the particles of ore by placing the which-the ore is immersed.

latter in a solution capable of yielding chlorin such as a soluble hypochlorite, and then adding'acid thereto but I prefer to generate and introduce the chlorin directly into the bodyof the unroasted ore by means of the electric current acting upon the SOllltlOn in may be a strong solution of hydrochloric acid (muriatic acid,-as known in trade) or a strong brine kept acid by hydrochloric or sulfuric 1 sulfids. fullyrealized, however, in practice, and there- The solutionacid. The current acting upon thissolution sets free chlorin, which in the presence of water combines with hydrogen and liberates oxygen, which oxidizes the sulfur of the ores,

converting the sulfids into sulfates. Theoretically only a relatively small rl liliantity-of chlorin would be necessary for-t sion, as is shown by the equation:

the chlorin set free by the current formin hydrochloricacid and free oxygen, the aci .thus produced being capable ofagain furnishing chlorln, which thus travels in a cycle.

The oxygen being liberated in the nascent state in immediatecontact with the sulfid particles oxidizes energetically. The hypochlorites and chlorates formed in this process are acted upon by the free mineral acid of thegsolution, which liberates their acid radicals to aid powerfullyfin oxidizing the This theoretical condition is not fore an excess of acid must be present to dissolve the metallic oxids, (and carbonates,) which may be in excess of the sulfur in combination. The conversion of the sulfur of the sulfids into sulfuric acid, however, furnishes enough of that acid to prevent the S OOIIVGT- consumption of any large quantity of free acid.

In theaccompanying drawings-I have illustion, in W ich- Figure 1 i Fig. 2- is a diagrammatic view of a number of tanks, showing them electrically connected. Fig. 3 is a detail view showing an anode and cathode, with the cathode enveloped in a linen cloth.

- In carrying outmy invention as applied to the extraction of copper from sulfid ores the ore is firstcrushed to a suitable fineness, say fortymesh orfiner. Thenwithout concentrat-- ing it is ready to be placed inthe-tanks or vats for treatment. The size and number of the tanks 'will depend upon the quantity of ore to-be treated daily and the means of sup-,

S an elevation in longitudinal section of a tank for treating the crushed ore...

1 trated ap aratus for carrying out my invenplying the current.- In remote places, at-

smallv mines, small independent generators.

run by 'gasolene-engines can be employed. They would necessarily be as light as possible on account of transportation, and in such places smalltanks would be used-.; 011 the other hand, at centers where sufficient power is available .or wheracurrent is supplied on the large scale large tanks like those'used in a-tonof crushed ore. illustrate the process, itmay be provided cyaniding might be used. with correspcndj' ingly large generators. A tank. four; feet by four feet by two feet could treat, say, Taking sucha tank to with a perforated removable false bottom, so arranged that the anodes and cathodes may pass through itand reach tothe bottom-ofthe tank. In the-absence-of such a false bot tom a layer of coarse gravel two or three inches deep-should be placed in the tankin.

orderto allow somedepth of electrolyte be carbon-rods nearly as high as the tank, con-- iron may be used in place of carbon.-. 1 The- V anodesand cathodes-should be connected in low the ore.- This should be covered with straw or cheese-cloth to-keep the oresepa Next arrange in therate to some extent. tank for anodes a series of carbon plates or nected together atthe top byasuita'bleconduct'or ext-ending from one side to the otherof the tank-and reaching to the bottointhereof and alternating with these and at intervals: of about two or three inchesfrom them other carbon plates or series of-rods to serve as As it is-notintended or desired to deposit copper upon these cathodes the object/being merely to generate chlorin in this. tank', they may have a much less'surface cathodes "than the anodes, and sheet-copper or even dependently to conductors outsidethe tank leading to the in linen. cloths to retain thecopper-whic 1 is precipitated; loosely upon them. The .pu lverized oreis: now; introduced and covered with the electrolyte, care beingtaken not to allow 'thelatter to reach the conductors at the top of'the carbon All metallic connections inside thetank should be varnished to protect them from the corrosive action of the fumes ofchlorin; The current is now turned gi nsits action, and-copper sulfate appears. in

thes'olution. As copper sulfid; ores contain sides ends, and bottomv formed iron, sulfate of-iron is also formed and-goes" into the solution. l is the tank,'having its top openandits of .suitable material.

2 is the removable false. bottom, having perforations3 and resting on suitable. sup ports 4 onthe-bottom of the tank. 1,.so as to forma space between the two bottoms to al low-some depth of the electrolyte below the ore.

The crushed ore 5 isshown asre'sting on I the falsebottom. 2 in the electrolyte- 6.

7 and: 8 are the anodes andi'cathodes arrangeddnpairsandextending through openproper poles-of the generator: Thecathodes s ou'ld preferably be envelo ed on and the chlorinisatonce liberated and beings 9 in the perforated bottom 2 from top to bottom of the tank 1. The anodes 7 and 8 are independentlyelectrically connected by.

means of the binding-posts. 10 and 11 to conductors 12 and 13, leading to the poles a generator 14. In Fig. 2 I have shown a number of tanks in Which'the anodes and cathodes are so electrically connected and a switchboard 15 for cutting in and out the current to the different tanks,

In Fig. 3 is shown a cathode enveloped in a linen cloth 1 6.

The current-for the tank described should be of low voltage-say-two or-: three but of sufficient amperage to generate a considerable voluineof chlorin in-ashort time, say two hundredainperes. The current can be turnedod from one tank w-hen the fluid isci-pitatedin the form of sponge or cement.

copper, which iscollected and may beshipped toa smelteror refinery, or, if facilities exist, it may be.- melted and run into ingots or shapes suitable for anodes and sold in that form. r The solution may be used over and over again.

In centers where there are facilities for 'electrodepositing copper the precipitation by iron scrap might be dispensed with and the copper solution-be run directly into vats used for electrodeposition and there deposited ifit. were found feasible to do so.

If the copper ore contains gold, theaction of thercurrent should be stopped long enough before tapping to insure the com lete chloridizing and solution of the go d, some of which may have been precipitatcd at the cathodeby the reducing action of the ferrous salt formed there. The chlorin will convert the ferrous into a ferric salt and dissolve the gold; The gold. may be precipitated by the addition. of ferrous sulfate to the solution ina separate tank previous to the precipitation of. the copper.

A relatively deep tank with vertical anodes and cathodes has been described as being better adapted to. the present purpose. It would not of course be a departure from the invention to use tanks with the anodes and cathodes arranged horizontally.

ICC

Althougii this process is described as ap plied to t centrated ore, it'is evident that it will operate-as well upon twen'ty-per-cent. ore and con- 5 centrates as" upon two-per-cent; ore.

By this rocess zinc sulfid'is converted into sulfate an passes into solution in the'same Way as copper.

The zinc may be recovered from the solution by-electrode osition and I0 subsequent melting. The sul Ids carrying 15 from the iron contained in the solution by I chemicalreagents and electrodeposition.

Having now described my invention; what I claim, anddesire to secure byLetters Patent is ll'The process herein described of ex-.

tracting metals from sulfid ores, which consists in converting the sulfids into sulfates by subjecting a'body of unroasted pulverized sulfid ore, freely distributed throughout a I '25 suitable acidified solution, to the action of chloriil saturatingsaid solution and recovering the metals from said solution.

tracting metals from sulfid ores, which con- 39 sists'i n converting the sulfids into sulfates by laclng unroasted pulverized "sulfid ore, eely distributed throughout an acid. elece treatment of low-grade uncon'- trolyte bath, capable of yieldingchlorin and then "subjecting said electrolyte to the action ofan electric current until the entire electrolytebath is saturated With chlorin.

3. The process herein described of exs tracting metalsfrom s'ulfid ores, which cons sists in converting the sulfids into sulfates, by;

placing and; freely distributingunroasted pulverized su'lfid ore in an acidified chlorid solution, and passing an electric currentv through saidsolution until the entire solution is saturated with chlorin. 4. The hereindescribed process of eartracting metals froms ulfid ores, containing gold; which consists in converting the sulfids into sulfates by placing the unroasted u]- verized sulfid ore, freely distributed throu out an electrolytic bath, capable of yielding chlorin; subjecting said electrolyteto the action'of an electric current until the entire electrolyte bath is saturated with chlorin;

interruptin the current to ermitthe chlorin to oxidize t e iron salts an effect a com 'lete solution of the gold, and then drawing 0 and precipitating the gold.

.In testimony whereof Ij-have signed. my

' name to thisspecification in the presence of 2.-Ihe method herein described of'ex-.

I v EDWARD W. CADY- 

